function start(){
	
	var challengers = document.getElementById('challengers');
	var n			= challengers.options.length;
	for (var i = 0 ; i < n ; i ++) {
		
		challengers.options[i].selected = true;
	}
}

function add(){
	
	var challengers = document.getElementById('challengers'); 
	var players 	= document.getElementById('players');
	var selected 	= new Array();
	var ignored 	= new Array();
	var n			= players.options.length;
	
	for (var i = 0 ; i < n ; i ++) {
		
		var option = new Option(
			players.options[i].text,
			players.options[i].value
		);
		if (players.options[i].selected) {
			
			selected.push(option);
		}
		else{
			
			ignored.push(option);
		}
	}
	
	for (var i = 0 ; i < n ; i ++) {
		
		players.options[0] = null;
	}
	
	for (var i = 0 ; i < selected.length ; i ++) {
		
		challengers.options[challengers.options.length] = selected[i];
	}
	
	for (var i = 0 ; i < ignored.length ; i ++) {
		
		players.options[players.options.length] = ignored[i];
	}
}

function remove(){
	
	var challengers = document.getElementById('challengers'); 
	var players 	= document.getElementById('players');
	var selected 	= new Array();
	var ignored 	= new Array();
	var n			= challengers.options.length;
	
	for (var i = 0 ; i < n ; i ++) {
		
		var option = new Option(
			challengers.options[i].text,
			challengers.options[i].value
		);
		if (challengers.options[i].selected) {
			
			selected.push(option);
		}
		else{
			
			ignored.push(option);
		}
	}
	
	for (var i = 0 ; i < n ; i ++) {
		
		challengers.options[0] = null;
	}
	
	for (var i = 0 ; i < selected.length ; i ++) {
		
		players.options[players.options.length] = selected[i];
	}
	
	for (var i = 0 ; i < ignored.length ; i ++) {
		
		challengers.options[challengers.options.length] = ignored[i];
	}
}